Dust-disposal heat-dissipation device with double cooling fans

ABSTRACT

A heat dissipation device includes a fin set, a cover, a first fan, a second fan and a control module. The fin set includes a plurality of cooling fins transversely spaced apart and has a substantially flat section at a bottom thereof for contacting a heat source. The cover includes a plate which covers a top surface of the fin set and has two inlets longitudinally spaced apart. The first and second fans are mounted in the two inlets of the cover for generating airflow toward front and rear top sections of the fin set respectively. Additionally, the control module is configured to either actuate the first and second fans upon receiving a working signal or execute the following steps upon receiving a dust-disposal signal: (a). turning on the first cooling fan and turn off the second cooling fan simultaneously for a period of time; and (b). turning on the second cooling fan and turn off the first cooling fan simultaneously for a period of time.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a heat dissipation device having doublecooling fans, and in particular to the one with dust removal function.

2. Related Prior Art

Computer components often exude a large amount of heat during operationof the computer system. In order to keep the components within theirsafe operating temperatures, heat generated by the components must bedissipated. Varied cooling apparatuses are used to remove heat fromcomputer components.

Taiwan Patent No. 371497 is exemplary of patent directed to a dual-fanheat dissipation device of the type to which this invention is directed.The dissipation device mainly includes two cooling fans and a fancontrol module for controlling rotation of the cooling fans. One of thefans is arranged to draw cooler air into a computer chassis from outsidewhile the other fan is to exhaust hot air out of the computer chassis.The fan control module is configured to enable the fans to run in turn.That is, when one fan rotates, the other stops, and they take turns. Inthis manner, resonance effect, which is often caused by a dual-fandevice in a computer system, may be reduced, and thereby the noise isdiminished. However, the dual-fan heat dissipation device as describedin that patent has no dust removal function.

Another heat dissipation device is described in U.S. Pat. No. 7,630,201and includes two fans which take turns to rotate in the oppositedirection to keep a heat sink cool. However, the fans are not able torun together at the same time for cooling the heat sink, and thereforethe heat dissipation efficiency of the same is limited.

SUMMARY OF INVENTION

Broadly stated, the present invention is directed to a dual-fan heatdissipation device with a dust removal function. The heat dissipationdevice generally includes a fin set, a cover, a first cooling fan, asecond cooling fan and a control module. The fin set includes aplurality of cooling fins alongside each other. The cover has a mainplate which covers a top of the fin set. The first and second coolingfans are disposed on the cover. Upon being actuated, the first coolingfan is able to generate airflow toward a front top section of the finset. Likewise, the second cooling fan is able to generate airflow towarda rear top section of the fin set upon being actuated. The controlmodule is configured to either actuate the first and second fans uponreceiving a working signal or execute the following steps upon receivinga dust-disposal signal:

(a). turning on the first cooling fan and turn off the second coolingfan simultaneously for a period of time; and

(b). turning on the second cooling fan and turn off the first coolingfan simultaneously for a period of time.

By virtue of the control module, during the time period of step (a), thefirst cooling fan generates airflow to have a heat exchange with thecooling fins of the fin set, as well as to remove dust from the fin setand the second cooling fan. In like manner, the second cooling fan isable to generate airflow to cool the fin set and remove dust from thefin set and the first cooling fan simultaneously during the time periodof step (b). In particular, in the aforementioned steps, the first andsecond cooling fans each rotates in the same direction without reverserotation.

Preferably, after the step (a) but before the step (b), the controlmodule further executes the step of simultaneously turning on the firstand second cooling fans. In this way, while the control module isshifting from step (a) to the step (b), a situation where both the firstand second cooling fans are both shut down can be avoided.

In addition, the fin set has a substantially flat section, a frontinclined section and a rear inclined section at a bottom thereof. Theflat section is defined for contacting a heat source. The front and rearinclined sections are located at opposite sides of the flat section. Thefront inclined section faces obliquely toward the first cooling fan. Therear inclined section faces obliquely toward the second cooling fan.Besides, the front and rear inclined sections are slanted toward theflat section. As such, the rear inclined section is able to direct airtoward the second cooling fan in step (a) and the front inclined sectiontoward the first cooling fan in step (b).

Further features and advantages of the present invention will beappreciated by review of the following detailed description of theinvention.

BRIEF DESCRIPTION OF DRAWINGS

The invention is illustrated by the accompanying drawings in whichcorresponding parts are identified by the same numerals and in which:

FIG. 1 is a perspective view of a circuit board and an embodiment of aheat dissipation device in according with the present invention;

FIG. 2 is another perspective view, partially exploded to show detailsof a bottom of a fin set of the heat dissipation device;

FIG. 3 is a cross-sectional view of the heat dissipation device, showingthe route of airflow when the two cooling fans are both in workingstates;

FIG. 4 is another cross-sectional view of the heat dissipation device,showing the route of airflow when only the left fan is in the workingstate; and

FIG. 5 is a view similar to FIG. 4, showing the route of airflow whenonly the right cooling fan is in the working state.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

Turning in detail to the drawings, a heat dissipation device isillustrated in FIGS. 1 and 2 in accordance with the preferred embodimentof the invention. The heat dissipation device includes a first coolingfan 1, a second cooling fan 2, a cover 3, a fin set 4 and a controlmodule 5. Note that, in this embodiment, the control module 5 isintegrated on a printed circuit board 8.

As shown in FIG. 1, the fin set 4 includes a plurality of cooling fins40 spaced apart in a transverse direction X. Channels are definedbetween adjacent cooling fins 40. The cover 3 includes a main plate 30and two baffles 31 extending downward from opposite sides of the mainplate 30. The main plate 30 covers a top surface of the fin set 4 andhas two inlets 301 and 302 defined therein and spaced apart in alongitudinal direction Y. The first cooling fan 1 is mounted in theinlet 301 of the cover 3. Upon being actuated, the first cooling fan 1is able to generate airflow toward a front top section of the fin set 4.Similarly, the second cooling fan 2 is mounted in the other outlet 302of the cover 3 and is able to generate airflow toward a rear top sectionof the fin set 4 upon being actuated.

The control module 5 is generally composed of a micro controller andsome transistor switch circuits, as will be described later.

As shown in FIG. 2, the fin set 4 has a substantially flat section 41 atthe bottom thereof for contacting a heat source 6. In this example, theheat source 6 includes a heat conductive block 61 and heat absorptionsections of some heat pipes 7. In another example, the heat source 6 maybe a CPU, a GPU or other heat-generating components.

As shown in FIG. 3, the flat section 41 of the fin set 4 contacts theheat source 6. The heat conductive block 61 of the heat source 6 abutsagainst a chip 80 of the circuit board 8. Therefore, heat generated bythe chip 80 can be transferred by the heat conductive block 61 and theheat pipes 7 to the fin set 4 for further dissipation.

As can be seen in FIGS. 3-5, the circuit board 8 is a computer displaycard inside a computer host. The chip 80 is a GPU integrated on thecomputer display card. The control module 5 is integrated on the circuitboard 8 and is coupled to the first and second cooling fans 1, 2 forpower control over the two cooling fans 1, 2 in order to selectivelyturn on or off the first and second cooling fans 1, 2. Most importantly,the control module 5 is configured to either actuate the first andsecond fans 1, 2 upon receiving a working signal or execute thefollowing steps upon receiving a dust-disposal signal:

(a). turning on the first cooling fan 1 and turn off the second coolingfan 2 simultaneously; and

(b). turning on the second cooling fan 2 and turn off the first coolingfan 1 simultaneously.

It is noted that each of the steps (a) and (b) is executed for apredetermined period of time, such as dozens of seconds or minutes.

There are a number of ways to generate the working signal. For instance,a push by a user via a quick launch button of a keyboard of the computerhost enables the computer host to generate a working signal. In anotherway, a working signal may also be generated by a program which drivesthe computer host to generate the same. In yet another way, the computerhost may be required to generate a working signal when a temperatureinside the computer host is detected by a temperature sensor and thetemperature value is above a criterion.

Similarly, there are a number of ways to generate a dust-disposalsignal. For instance, by a push of another button (such as a buttonspecial created for dust removal) on the computer host or another quicklaunch button. In another way, a dust-disposal signal may be generatedby the computer host by means of a computer program. In yet another way,the computer host may be required to generate a dust-disposal signalonce a total operating time value of the first and second cooling fansis up to a predetermined standard value.

In any case, upon receiving the working signal, the control module 5immediately actuates the first and second cooling fans 1, 2 for heatdissipation. That is, the control module 5 allows the first and secondcooling fans 1, 2 to be powered in such a way that the first and secondcooling fans 1, 2 are able to generate airflow, as shown by arrows inFIG. 3. In this state, the first and second cooling fans 1, 2 areoperating for heat dissipation from the circuit board 8 and the chip 80.As can be seen from arrows in FIG. 3, particles A, such as dust orfeather dust, are remained on a surface of the fin set 4, namely a fronttop edge 40 a and a rear top edge 40 b, which face the direction of theairflow. Besides, on the surfaces of the fan blades of the first andsecond cooling fans 1, 2 are particles (not shown) too.

In particular, once the control module 5 receives the dust-disposalsignal, the control module 5 executes the aforementioned steps (a) and(b) to cast out those particles. Firstly, in step (a), the first coolingfan 1 is turned on and working while the second cooling fan 2 is turnedoff and stops working, under the control of the control module 5. Atthis time, the first cooling fan 1 generates airflow as shown by arrowsin FIG. 4. According to the direction of the airflow in FIG. 4, thoseparticles A accumulated on the rear top edge 40 b of the fin set 4 aswell as the particles which are on the blades of the second cooling fan2 are blew off by the airflow of the first cooling fan 1. Note that, inaddition to the dust removal, the first cooling fan 1, in the meanwhile,runs for heat dissipation.

Secondly, in step (b), the first cooling fan 1 is turned off and stopsworking under the control of the control module 5. However, the secondcooling fan 2 is turned on by the control module 5 and starts to run togenerate airflow as shown by arrows in FIG. 5. According to thedirection of the airflow in FIG. 5, those particles A accumulated on thefront top edge 40 a of the fin set 4 as well as the particles which areon the blades of the first cooling fan 1 are blew off by the airflow ofthe second cooling fan 2. Also note that, in addition to the dustremoval, the second cooling fan 2, in the meanwhile, runs for heatdissipation.

As described above, when the computer host generates the dust-disposalsignal, the control module 5 receives the signal and then executes thesteps (a) and (b) to enable the first and second cooling fans 1, 2 toremove the dust in turn. If necessary, the control module 5 can furtherexecutes another round of the steps (a) and (b) each for a while andrepeats that over and over again. Anyhow, it can be understood that, byvirtue of the control of the control module 5 over the first and secondcooling fans 1, 2, the fin set 4 as well as the first and second coolingfans 1, 2 can be kept clean without dust accumulation, which hassignificant positive effect on the heat-dissipation-efficiency of theentire heat dissipation device.

It should be noted that when being actuated by the control module 5 toexecute the regular heat dissipation process, the two cooling fans 1, 2both rotate in a rotational direction. In addition to that, in responseto the dust-disposal signal, the control module 5 drives the first andsecond cooling fans 1, 2 to continue rotating in the same rotationaldirection. These greatly differ from the prior arts where the coolingfans are constructed to rotate reversely for dust removal purpose.

While the first and second cooling fan 1, 2 are taking turns to run asmentioned in the steps (a) and (b), it may happen that the two coolingfans 1, 2 are shutting down simultaneously in a short time. This mayhappened due to a circuit delay, for example. Sometimes the result,because of the short shutdown, could also be incorrectly deemed as aproblem by a user. In this regard, the control module 5 may be furtherconfigured to execute the step of simultaneously turning on the firstand second cooling fans 1, 2, after the step (a) but before the step(b), so as to prevent the two cooling fans 1, 2 from shutting down atthe same time.

In this preferred embodiment, the control module 5 is integrated on thecomputer display card; however, in other embodiments, it may also beintegrated on a mother board of the computer host. In either way, theresources of GPU on the display card or CPU on the mother board can beemployed to replace the micro controller of the control module 5.Alternatively, the control module 5 may be an independent circuitmodule.

Referring back to FIG. 2, the fin set 4 has the bottom including a frontinclined section 42 and a rear inclined section 43 on opposite sides ofthe flat section 41. The front and rear inclined sections 42, 43 areslanted toward the flat section 41, as shown in FIG. 3. The cooling fins40 of the fin set 4 are placed side by side and joined together. Eachcooling fin 40, substantially fabricated by metal punching process, ismade of copper or aluminum. Each cooling fin 40 includes a base plate401 together with a middle folded edge 402, a front oblique folded edge403 and a rear oblique folded edge 404 each extending from a bottom ofthe base plate 401. Those middle folded edges 402 of the cooling fins 40together define the flat section 41 of the fin set 4. Those frontoblique folded edges 403 of the cooling fins 40 together define thefront inclined section 42 of the fin set 4. Also, those rear obliquefolded edges 404 of the cooling fins 40 together define the rearinclined section 43 of the fin set 4. However, this is simply an exampleof the fin set 4; and the fin set 4 may be made by any other way, suchas by aluminum extrusion process.

Additionally, the front inclined section 42 of the fin set 4 facesobliquely towards the first cooling fan 1 while the rear inclinedsection 43 of the fin set 4 faces obliquely toward the second coolingfan 2. As shown in FIG. 4, the rear inclined section 43 of the fin set 4is constructed to guide airflow towards the second cooling fan 2. On theother hand, the front inclined section 42 of the fin set 4 is to guideairflow towards the first cooling fan 1, as depicted in FIG. 5. However,the front and rear inclined sections 42, 43 of the fin set 4 may bedeleted from the entire device without substantially affectingperformance.

It will be appreciated that although a particular embodiment of theinvention has been shown and described, modifications may be made. It isintended in the claims to cover such modifications which come within thespirit and scope of the invention.

1. A heat dissipation device, comprising: a fin set including aplurality of cooling fins transversely spaced apart and having asubstantially flat section at a bottom thereof for contacting a heatsource; a cover including a main plate which covers a top surface of thefin set and has two inlets defined therein and longitudinally spacedapart; and a first cooling fan mounted in one of the two inlets of thecover for generating airflow toward a front top section of the fin set;a second cooling fan mounted in the other inlet of the cover forgenerating airflow toward a rear top section of the fin set; and acontrol module configured to either actuate the first and second fansupon receiving a working signal or execute the following steps uponreceiving a dust-disposal signal: (a). turning on the first cooling fanand turn off the second cooling fan simultaneously for a period of time;and (b). turning on the second cooling fan and turn off the firstcooling fan simultaneously for a period of time.
 2. The heat dissipationdevice of claim 1, wherein after the step (a) but before the step (b),the control module further executes the step of turning on the first andsecond cooling fans simultaneously.
 3. The heat dissipation device ofclaim 1, wherein the bottom of the fin set further has a front inclinedsection and a rear inclined section on opposite sides of the flatsection; and the front and rear inclined sections face obliquely towardsthe first and second cooling fans respectively and both are slantedtoward the flat section.
 4. The heat dissipation device of claim 2,wherein the bottom of the fin set further has a front inclined sectionand a rear inclined section on opposite sides of the flat section; andthe front and rear inclined sections face obliquely towards the firstand second cooling fans respectively and both are slanted toward theflat section.
 5. A control module employed to control a first coolingfan and a second cooling fan and configured to either actuate the firstand second fans upon receiving a working signal or execute the followingsteps upon receiving a dust-disposal signal: (a). turning on the firstcooling fan and turn off the second cooling fan simultaneously for aperiod of time; and (b). turning on the second cooling fan and turn offthe first cooling fan simultaneously for a period of time.
 6. Thecontrol module of claim 5, wherein after the step (a) but before thestep (b), the control module further executes the step of turning on thefirst and second cooling fans simultaneously.
 7. A fin set comprising aplurality of cooling fins transversely spaced apart, and having asubstantially flat section, a front inclined section and a rear inclinedsection at a bottom thereof; the flat section situated in between thefront and rear inclined sections for contacting a heat source; and thefront and rear inclined sections being slanted toward the flat section.